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- Go to menu Data, tab Concept
- In the left panel, browse/search for the concept you want to delete. Select it
- in the right panel, click on the downward pointing arrow next to the cogwheel
- click on Set as deprecated
The blu blue ball next to the Concept name (in both panels) will become grey and in box “Other properties” (right panel) you will see a property “owl:deprecated" with value "true”
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